I've use the DX 21 for about 5 months now, and I think it's a pretty nice tihng to play around with. The sounds are really of no use as-is (except the hi-hats), but with an external FX-box or filter it's possible to get some quite nice top-beats out of it. But of course that, and much more, is possible with any rhythm box. Only two (left and right) outputs give no possibilities of adding effects to individual sounds, which would be the only way to make something really useful with the DX 21. It's cheap, but for about 40USD more, you could get a much more useful rhythm box (e.g. TR-707, with 10 outs...). Think twice before you buy this one.

Comments About the Sounds:
Not possible to modify the sounds in any way.